Offcenter butt joint for cartons



E. G. THIELE OFFCENTER BUTT JOINT FOR CARTONS Aug. 20, 1968 Filed April17, 1967 FIG. .2

INVENTOR. Eon/42a 6. 791542-- lrraku'ys United States Patent 3,397,832OFFCENTER BUTT JOINT FOR CARTONS Edward G. Thiele, Minneapolis, Minn.,assignor to Cherry-Burrell Corporation, Minneapolis, Minn., acorporation of Delaware Filed Apr. 17, 1967, Ser. No. 631,226 3 Claims.(Cl. 229-37) ABSTRACT OF THE DISCLOSURE The present disclosure relatesto a five panel carton' having an oil center top butt joint andconstructed to have good carton strength (resistance to splitting) intransverse direction without having a strip of tape across the top seamor without lapping and gluing the top panels on the carton. This permitsthe use of a perforated inner liner in the corrugated paper board usedfor making the carton to facilitate opening. When erected, the carton ofthe invention has two top panels that meet along a butt joint that isadjacent one edge of the carton. Each of the top panels has an end paneland these end panels fold down along the ends of the carton. Theportions of the end panels that are adjacent the seam between the twotop panels are glued to the same end flap (attached to the side panelsof the carton) so that there is structural strength preventing the seambetween the top end panels from separating when the carton is loaded ina transverse direction.

BACKGROUND OF THE INVENTION 1) Field of the invention.The inventionrelates to cartons particularly for shipping case loads of can goods andusing five panels, a minimum amount of cardboard, and having glued endjoints.

(2) Description of the prior art-In standard shipping cartons, severalforms are used. Some cartons use overlapped joints at the end panels,such as that shown in US. Patent No. 3,209,981. In this patent the toplap joint at the top of the carton is left unsealed to permit easyopening of the carton, while the lap joint at the ends is glued to givethe carton structural strength in transverse direction when it isclosed. However, this leaves an irregularity (two thicknesses of paperboard) on the top of the carton making stacking somewhat difficult andalso this lap has a tendency to hook when cartons are slid ofi oneanother. The lap joints use more paperboard, and when the quantities ofcartons are high this becomes a significant factor.

The standard cartons using five panels have a butt joint down the topcenter of the carton, but these cartons then do not have a great deal ofstructural strength because the butt joint is unfastened unless aconventional tape seam or similar device is employed. The boxes thentend to split along this butt joint because they are not held togetherat the ends.

Other cartons have a single cover panel with a flap attached to thecover and folded against and glued to one side panel of the carton.These cartons are more expensive to make and more difficult to glueclosed.

SUMMARY OF THE INVENTION The present invention relates to the formationof a five panel carton having an untaped, unglued off center butt jointbetween two cover or top panels which permits easy opening of the cartonto remove canned goods stored inside the end panels attached to thecover or top panels are glued to a common end flap to provide for goodtransverse strength when the carton is closed. Ofr' setting the buttjoint between the top panels so that the joint or seam is adjacent oneside of the carton, aligns the joint with a 'ice common end flapattached to the side panel of the carton. By gluing to a common endflap, the joint on the ends of the carton do not tend to separate afterit has been glued.

DESCRIPTION OF THE DRAWING FIGURE 1 is a flat plan layout of a cartonblank made according to the present invention;

FIGURE 2 is a perspective view showing the carton at its initial stagesof being folded;

FIGURE 3 is a perspective view of the device of FIG- URE 2 showing thecarton partially closed; and

FIGURE 4 is a perspective View of the carton after it has been fullyassembled with a product inside the carton.

Referring to the drawings and the numerals of reference thereon, acarton or box illustrated generally at 10 is made from a blank 11 havingfive panels. The blank has a bottom panel 12, a first side panel 13 anda second side panel 14, both attached to the bottom panel 12. A firsttop panel 15 is attached to the first side panel 13 and a second toppanel 16 is attached to the second side panel 14. As shown, the panelsare all hinged to each other so that they can be folded along theirjunction lines.

In forming the carton for loading product into it, the product isusually placed on the bottom panel and the side panels are foldedupwardly as shown in FIGURE 2. Then after the carton has been filled(usually with canned goods) the top panels 15 and 16 are folded toposition as shown in FIGURE 3. In order to close the ends of thecartons, at each end of the carton the construction is identical. Theside panel 13 has two first end flaps 17 attached thereto (at oppositeends), and side panel 14 has two second end flaps 18 attached thereto atopposite ends. Bottom panel 12 has two lower end panels 21 attachedthereto, one at each end. First top panel 15 has two cover end panels 22attached thereto and second top panel 16 has two short cover end panels23 attached thereto.

The end flaps 17 and 18 are spaced, as shown, and in any event are notfastened together.

In assembly, the end fi-aps 17 and 18 are folded in so they areparallel. Glue strips indicated at 24 are applied to the lower endpanels in position so that when the bottom or lower end panels 21 arefolded up they will contact and be glued to the aligning end flaps 17and v18. Glue strips 25 and 26 are placed on cover or upper end panels22 and glue strips 28 are applied to cover or upper end panels 23. Itwill be noted that the joint 27 is positioned adjacent to side panel 14and is in alignment with the end flap 18.

Then, the carton is closed as shown in FIGURE 3 and the glue strips 26and 28 contact the end flaps 18 (the other glue strips contact the endflaps as well) and will hold the end panel 22 and end panel 23 at eachend against the same end flap 18. This means that the upper end panels22 and 23 cannot separate along line 27 at the ends of the carton. Thuswhen there are forces tending to cause the carton to separate, such asforces shown by the arrows 30, the load is transferred to the end panels22 and 23 and these are held together by the glue strips 26 and 28 tothe common end flap 18 so that there is no weakness in the ends of thebox which permit the box to split open easily. If for example the buttjoint was along the line shown at dotted lines in 31 as is common to thepresent time, the joint between the two end panels attached to the toppanels would be open, unattached, and the carton or box would tend tosplit along this line. Applying tape to this joint or seam is difiicultto do and involves additional expense.

As shown in FIGURE 1, there are perforations on the inner sheet of paperon the corrugated carton and these perforations are indicated at 32.These perforations will provide a guide for easy opening of the carton.-In the present invention the joint 27 is open between the two top panelsand 16 and this permits a person wanting to open the carton to removethe product to insert his hand between'panls 15 and '16 and easily tearthe carton open guided by these perforations; With lap joints that areglued of course; the-carton cannot be easily opened and the advantagesof the easy opening perforations are not present. Where butt joints areused, normally. the butt joint is in the center of the case and thismakes the case much less desirable for shipping cans and the likebecauseof the weaknesses. The present invention eliminates this weakness andsaves cost over lap joints such as that shown in Patent No. 3,209,981 aswell as making the cartons fiat across the top and easier to stack;

Perhaps a word about the easy opening perforations mentioned previouslywould be in order. As is known, there are two layers of kraft paper witha paper corrugation inbetween in making corrugated paper board. WaldorfPaper Company has-advanced the improvement of perforating the innerliner only of the kraft paper so that easy tear or a guided tear can bemade. The outer liner of kraft paper is not perforated so the cartondoes not lose any substantial amount of strength, but merely has a guidefor opening. By using the butt joint disclosed, this improvement isavailable because the person removing the product can insert his hand totear the panels along the perforations. Yet, the carton is as strong asthe conventional RSC cartons and is still able to be stacked wellbecause it has a flat top and does not have any lapped joints forwasting the cardboard.

What is claimed is:

1. A shipping case filled with a product to be shipped, said casecomprising a bottom panel having opposite ends, a pair of side panelsjoined to said bottom panel and extending substantially at right anglesthereto, each side panel having opposite ends, an end flap for 'eachside panel end joined to'the respective side panel and extending towardthe opposite side panel, a bottom end panel attached to each end ofsaidbottom panel extending upwardly -to overlie the end flaps, firstandsecond top cover panels, one hingedly attached toeach of said sidepanels,- said cover panels each having a pair of cover endpanels'attached thereto at opposite ends thereof, said cover panelsbeing co-planar'when in positionsubsta ntially parallel tothe bottompanel and covering' sai'd car ton and edges thereof being adjacent alongabutt joint, said cover end 'panels being' folded to overlie said endflaps on each end of the case and being' co-planar with andsubstantially abutting said bottom end panels and glue means to holdsaid coverend panels and said bottom end panels against said end flapsand'comprising the sole fastening means for the shipping casegat least aportion of each of the cover end panels at each 'er'id'of thecartonbeing secured to'a common endfiap.

2. The combination as specified in claim l' wherein the end flaps arespaced apart a substantial distance when closed, and wherein the coverpanels are of size so that the joint between the cover panels ispositioned adjacent to one of said side panels.

3. The combination as specified'in claim -1 wherein the end flaps on thesame end of the case and on opposite side panels are spaced apart.

References Cited UNITED STATES PATENTS 1,555,045 9/ 1925 Walter 2294 8 X3,085,734 4/1963 Kauifeld 229'-51 3,209,981 10/1965 Thiele 229-48 DAVIDM. BOCKENEK, Primary Examiner.

